#define MD5_EXPORTS

#include <string.h>
#include "Md5Sum.h"
//#include "../Logger/Logger.h"
#pragma warning(disable:4996)

void md5_init(MD5_CONTEXT *ctx)
{
    ctx->A = 0x67452301;
    ctx->B = 0xefcdab89;
    ctx->C = 0x98badcfe;
    ctx->D = 0x10325476;
    ctx->nblocks = 0;
    ctx->count = 0;
}

/****************
* transform n*64 bytes
*/
void transform(MD5_CONTEXT *ctx, unsigned char *data)
{
    unsigned int correct_words[16];
    unsigned int A = ctx->A;
    unsigned int B = ctx->B;
    unsigned int C = ctx->C;
    unsigned int D = ctx->D;
    unsigned int *cwp = correct_words;

    memcpy(correct_words, data, 64);

#define OP(a, b, c, d, s, T)			  \
    do								      \
        {								      \
        a += FF (b, c, d) + (*cwp++) + T; \
        a = rol(a, s);					  \
        a += b;							  \
        }								      \
            while (0)

    /* Before we start, one word about the strange constants.
    They are defined in RFC 1321 as

    T[i] = (int) (4294967296.0 * fabs (sin (i))), i=1..64
    */

    /* Round 1.  */
    OP(A, B, C, D, 7, 0xd76aa478);
    OP(D, A, B, C, 12, 0xe8c7b756);
    OP(C, D, A, B, 17, 0x242070db);
    OP(B, C, D, A, 22, 0xc1bdceee);
    OP(A, B, C, D, 7, 0xf57c0faf);
    OP(D, A, B, C, 12, 0x4787c62a);
    OP(C, D, A, B, 17, 0xa8304613);
    OP(B, C, D, A, 22, 0xfd469501);
    OP(A, B, C, D, 7, 0x698098d8);
    OP(D, A, B, C, 12, 0x8b44f7af);
    OP(C, D, A, B, 17, 0xffff5bb1);
    OP(B, C, D, A, 22, 0x895cd7be);
    OP(A, B, C, D, 7, 0x6b901122);
    OP(D, A, B, C, 12, 0xfd987193);
    OP(C, D, A, B, 17, 0xa679438e);
    OP(B, C, D, A, 22, 0x49b40821);

#undef OP
#define OP(f, a, b, c, d, k, s, T)               \
    do								             \
        { 							                 \
        a += f (b, c, d) + correct_words[k] + T; \
        a = rol(a, s);						     \
        a += b; 						         \
        } 							                 \
            while (0)

    /* Round 2.  */
    OP(FG, A, B, C, D, 1, 5, 0xf61e2562);
    OP(FG, D, A, B, C, 6, 9, 0xc040b340);
    OP(FG, C, D, A, B, 11, 14, 0x265e5a51);
    OP(FG, B, C, D, A, 0, 20, 0xe9b6c7aa);
    OP(FG, A, B, C, D, 5, 5, 0xd62f105d);
    OP(FG, D, A, B, C, 10, 9, 0x02441453);
    OP(FG, C, D, A, B, 15, 14, 0xd8a1e681);
    OP(FG, B, C, D, A, 4, 20, 0xe7d3fbc8);
    OP(FG, A, B, C, D, 9, 5, 0x21e1cde6);
    OP(FG, D, A, B, C, 14, 9, 0xc33707d6);
    OP(FG, C, D, A, B, 3, 14, 0xf4d50d87);
    OP(FG, B, C, D, A, 8, 20, 0x455a14ed);
    OP(FG, A, B, C, D, 13, 5, 0xa9e3e905);
    OP(FG, D, A, B, C, 2, 9, 0xfcefa3f8);
    OP(FG, C, D, A, B, 7, 14, 0x676f02d9);
    OP(FG, B, C, D, A, 12, 20, 0x8d2a4c8a);

    /* Round 3.  */
    OP(FH, A, B, C, D, 5, 4, 0xfffa3942);
    OP(FH, D, A, B, C, 8, 11, 0x8771f681);
    OP(FH, C, D, A, B, 11, 16, 0x6d9d6122);
    OP(FH, B, C, D, A, 14, 23, 0xfde5380c);
    OP(FH, A, B, C, D, 1, 4, 0xa4beea44);
    OP(FH, D, A, B, C, 4, 11, 0x4bdecfa9);
    OP(FH, C, D, A, B, 7, 16, 0xf6bb4b60);
    OP(FH, B, C, D, A, 10, 23, 0xbebfbc70);
    OP(FH, A, B, C, D, 13, 4, 0x289b7ec6);
    OP(FH, D, A, B, C, 0, 11, 0xeaa127fa);
    OP(FH, C, D, A, B, 3, 16, 0xd4ef3085);
    OP(FH, B, C, D, A, 6, 23, 0x04881d05);
    OP(FH, A, B, C, D, 9, 4, 0xd9d4d039);
    OP(FH, D, A, B, C, 12, 11, 0xe6db99e5);
    OP(FH, C, D, A, B, 15, 16, 0x1fa27cf8);
    OP(FH, B, C, D, A, 2, 23, 0xc4ac5665);

    /* Round 4.  */
    OP(FI, A, B, C, D, 0, 6, 0xf4292244);
    OP(FI, D, A, B, C, 7, 10, 0x432aff97);
    OP(FI, C, D, A, B, 14, 15, 0xab9423a7);
    OP(FI, B, C, D, A, 5, 21, 0xfc93a039);
    OP(FI, A, B, C, D, 12, 6, 0x655b59c3);
    OP(FI, D, A, B, C, 3, 10, 0x8f0ccc92);
    OP(FI, C, D, A, B, 10, 15, 0xffeff47d);
    OP(FI, B, C, D, A, 1, 21, 0x85845dd1);
    OP(FI, A, B, C, D, 8, 6, 0x6fa87e4f);
    OP(FI, D, A, B, C, 15, 10, 0xfe2ce6e0);
    OP(FI, C, D, A, B, 6, 15, 0xa3014314);
    OP(FI, B, C, D, A, 13, 21, 0x4e0811a1);
    OP(FI, A, B, C, D, 4, 6, 0xf7537e82);
    OP(FI, D, A, B, C, 11, 10, 0xbd3af235);
    OP(FI, C, D, A, B, 2, 15, 0x2ad7d2bb);
    OP(FI, B, C, D, A, 9, 21, 0xeb86d391);

    /* Put checksum in context given as argument.  */
    ctx->A += A;
    ctx->B += B;
    ctx->C += C;
    ctx->D += D;
}

/* The routine updates the message-digest context to
* account for the presence of each of the characters inBuf[0..inLen-1]
* in the message whose digest is being computed.
*/
void md5_write(MD5_CONTEXT *hd, unsigned char *inbuf, size_t inlen)
{
    if (hd->count == 64)
    { /* flush the buffer */
        transform(hd, hd->buf);
        hd->count = 0;
        hd->nblocks++;
    }

    if (NULL == inbuf)
    {
        return;
    }

    if (hd->count)
    {
        for (; inlen && hd->count < 64; inlen--)
        {
            hd->buf[hd->count++] = *inbuf++;
        }

        md5_write(hd, NULL, 0);
        if (0 == inlen)
        {
            return;
        }
    }

    while (inlen >= 64)
    {
        transform(hd, inbuf);
        hd->count = 0;
        hd->nblocks++;
        inlen -= 64;
        inbuf += 64;
    }

    for (; inlen && hd->count < 64; inlen--)
    {
        hd->buf[hd->count++] = *inbuf++;
    }
}

/* The routine final terminates the message-digest computation and
* ends with the desired message digest in mdContext->digest[0...15].
* The handle is prepared for a new MD5 cycle.
* Returns 16 bytes representing the digest.
*/

void md5_final(MD5_CONTEXT *hd)
{
    unsigned int t, msb, lsb;
    unsigned char *p;

    md5_write(hd, NULL, 0); /* flush */;

    t = hd->nblocks;
    /* multiply by 64 to make a byte count */
    lsb = t << 6;
    msb = t >> 26;
    /* add the count */
    t = lsb;
    if ((lsb += hd->count) < t)
        msb++;
    /* multiply by 8 to make a bit count */
    t = lsb;
    lsb <<= 3;
    msb <<= 3;
    msb |= t >> 29;

    if (hd->count < 56)
    { /* enough room */
        hd->buf[hd->count++] = 0x80; /* pad */
        while (hd->count < 56)
        {
            hd->buf[hd->count++] = 0;  /* pad */
        }
    }
    else
    { /* need one extra block */
        hd->buf[hd->count++] = 0x80; /* pad character */
        while (hd->count < 64)
        {
            hd->buf[hd->count++] = 0;
        }

        md5_write(hd, NULL, 0);  /* flush */;
        memset(hd->buf, 0, 56); /* fill next block with zeroes */
    }

    /* append the 64 bit count */
    hd->buf[56] = lsb;
    hd->buf[57] = lsb >> 8;
    hd->buf[58] = lsb >> 16;
    hd->buf[59] = lsb >> 24;
    hd->buf[60] = msb;
    hd->buf[61] = msb >> 8;
    hd->buf[62] = msb >> 16;
    hd->buf[63] = msb >> 24;
    transform(hd, hd->buf);

    p = hd->buf;

    X(A);
    X(B);
    X(C);
    X(D);
}

bool GetMd5Sum(const std::string& strFilePath, std::string& strMd5Sum)
{
    FILE *fp = NULL;
    unsigned char buffer[4096] = { 0 };
    size_t n = 0;
    MD5_CONTEXT ctx;
    int i = 0;
    char md5sum_buffer[32] = { 0 };
    fp = fopen(strFilePath.c_str(), "rb");
    if (NULL == fp)
    {
        //L_ERR(AG, "[GetMd5Sum]Can't open {}, error:{}.", strFilePath, errno);
        return false;
    }

    md5_init(&ctx);
    while ((n = fread(buffer, 1, sizeof buffer, fp)))
    {
        md5_write(&ctx, buffer, n);
    }

    if (ferror(fp))
    {
       // L_ERR(AG, "[GetMd5Sum]Error reading {}, error:{}.", strFilePath, errno);
        fclose(fp);
        return false;
    }

    md5_final(&ctx);
    fclose(fp);
    for (i = 0; i < 16; i++)
    {
        sprintf_s(md5sum_buffer, "%02x", ctx.buf[i]);
        strMd5Sum.append(md5sum_buffer);
    }

    //L_INFO(AG, "[GetMd5Sum]Success, File:{}, MD5:{}", strFilePath, strMd5Sum);
    return true;
}
